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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../vue.js"></script>

</head>
<body>
    <div id="app">
        <!-- click沿用dom2的方法，不需要加on -->
        <!-- 条件语句需要写全，if,else if  ,he else作为结束 -->
        <button @click="count+=10">累加</button>
        <button @click="count-=10">累减</button>
        <h1 v-if="count>=90">A</h1>
        <h1 v-else-if="count>=80">B</h1>
        <h1 v-else-if="count>=70">C</h1>
        <h3 v-else>D</h3>
    </div>
    <script>
        Vue.config.productionTip = false;
        const vm = new Vue({
            el:'#app',
            data(){
                return {
                    count:0
                }
            }
        })


    </script>
</body>
</html>